Shipping Container with a Protective Coating

ABSTRACT

A shipping container is coated, at least in part, with a protective polymer coating. Commercial shipping containers may be handled roughly, so damage is common especially with plastic containers. The protective coating improves the durability, scuff and chip resistance to make the container more safe for long life and use.

The present application claims the benefit of U.S. Provisional Application No. 62/453,187, filed Feb. 1, 2017 and entitled Protective Coating for Folding, Lightweight, Hygienic, Heavy-Duty Food Shipping Container, which is incorporated by reference herein in its entirety.

The field of the present invention is lightweight, heavy-duty, bulk shipping containers. These containers are widely used in the movement of food products. Specifically, the present invention is directed to a shipping container that has a protective coating on it and that can be reliably cleaned for reuse.

BACKGROUND

At present, the food industry uses large shipping containers to move a broad range of food products across the country and around the world. These containers are large enough to hold hundreds and even thousands of pounds. A very common type of food shipping container is a single-use corrugated paper container that is moved around on a heavy wooden pallet. These containers and pallets are relatively heavy, and they are expensive and inefficient in that they may only be used a single time before disposal is required. The corrugated paper structure of these containers is not heavy-duty enough for reuse. Furthermore, the corrugated material cannot be reused for hygienic reasons because the container cannot be thoroughly washed and cleaned for reuse. Furthermore, these containers put a greater burden on landfills because contaminated corrugated boxes are very difficult to recycle (no one wants them because they have bacteria, E. coli, salmonella, campylobacter, etc. and they smell bad).

Reusable, plastic containers are known for use. However, existing containers may be too heavy for commercially economical reuse. Also, existing plastic containers have nooks and crevices and other engineering details that make them very difficult, if not virtually impossible, to reliably clean and inspect for cleanliness. Additionally, most existing plastic boxes are made of inexpensive polypropylene or polyethylene and therefore periodically plastic parts break off during use and contaminate the food product.

Current food containers/boxes are used in very high volume (high use) industries, but these current reusable products are subject to nicks, scratches, and abrasions from forklifts or other handling conditions. These nicks, cracks, scratches and abrasions can create a damaged surface that can harbor bacteria and harmful pathogens, thus contaminating the food contents and spreading contamination from one location to another. Additionally, pieces whatever a reusable container is made of—e.g., plastic, composite, or any other material, can be broken off and the broken parts fall into the food processing environment thus contaminating the food product and causing recalls.

SUMMARY

Accordingly, it is an object of the present to provide a coating to protect a plastic or composite or other material that a reusable container/box is manufactured from. The container is designed and engineered to have a protective layer that will not scratch and also will absorb impact from forklifts and other industrial equipment so that the structure of the container is not damaged. The protective layer or coating may be applied by over-molding, insert molding, cast molded, or spray on, or may be brushed on or applied on by heat transfer. The coating or protective layer may be applied to all or part of the base and sidewalls of a container. It may be applied only to one particular wear area or the whole container. The container is engineered to be able to be reliably cleaned for reuse in the industry.

In one example, a reusable container comprises a base, two folding sidewalls, two folding end walls and latches and hinges. The base comprises a rectangular platform having four corner portions fixed at each of the four corners of the base platform respectively. Bottom sides of the end walls and bottom sides of the sidewalls include the hinges and are hingedly connected to the base, wherein the end walls and the sidewalls are mounted on opposite sides of the base respectively; and further wherein each end wall comprises a latch that engages an adjacent sidewall when the sidewall and end wall are rotated in the up position substantially normal to the plane of the bottom of the box. The base further comprises a plurality of feet attached thereto on the opposite side of the platform from the corner portions. The base, sidewalls and end walls are at least partially coated with a protective polymer. The base, two folding sidewalls and two folding end walls may be comprised of plastic. The plastic may further comprise a polyester resin, vinyl ester resin, polyurethane, fiberglass, carbon fiber, polypropylene, polyethylene, ABS, or nylon or other polymer. The feet may be substantially monolithic and include essentially no exposed crevices therein. The feet may be comprised of polyurethane and are mechanically fastened to the base of the box. The base may be entirely coated with the polymer. The protective polymer coating may be a urethane product that is applied to the container by overmolding, insert molding, cast molding, compression molding or compression injection molding. The protective polymer coating may have a thickness of about 0.01 mm to 15 mm.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a container that includes a protective coating around the top of the sidewalls and end walls and around the base.

FIG. 2 is a perspective view of a cutaway of a bottom corner of the container shown in FIG. 1.

FIG. 3 is a bottom view of a container base that includes the cutaway, angular lines showing a protective coating protecting the bottom and sides of the base.

DETAILED DESCRIPTION

The container described herein includes a protective polymer coating on at least a part or alternatively its entire surface in order to protect the integrity and structure of the container material. The protective polymer coating protects the container from the typical rigors of daily use. The coating helps prevent the container from cracking or chipping as a result of mistreatment of the container in use.

In one example, a reusable, sanitary and folding container includes a base, two folding sidewalls, two folding end walls and latches and hinges. The base includes a rectangular platform having four corner portions fixed at each of the four corners of the base platform respectfully. The two folding sidewalls are rectangular surfaces, each sidewall comprising two hinge pins that extend outwardly from two corners along a bottom side of each rectangular sidewall. The hinge pins are received in two of the vertical slots of the adjacent corner portions so that the bottom sides of the sidewalls are hingedly connected to the base. The sidewalls are mounted on opposite sides of the base. Each sidewall comprises a U-shaped channel or a compression latch or other type of latch that is attached to opposite side edges that are each perpendicular to the bottom sides of the sidewalls. The U-shaped channel includes a latch pin fixed across the channel and proximate a top side of the sidewalls and the end of the U-shaped channel opposite the bottom side of the sidewalls. The latch comprises a slot for engaging the latch pin of an adjacent sidewall when the sidewall and end wall are rotated in the up position substantially normal to the plane of the bottom of the box. The latches and hinges are designed to be a system of two parts that work together, one will not work without the other.

The latch on each side of each end wall may comprise a flange having an L-shape latch groove therein adapted to receive and engage the latch pin of the adjacent sidewall. This is to prevent a sidewall from decoupling or collapsing inward when used in a hydraulic dumper. Alternatively, the latch on each side of each end wall comprises an L-shaped finger adapted to hook over and engage the latch pin of the adjacent sidewall.

An additional option for a container as described herein is a non-folding box that nests together, one inside the other for return shipment.

The container, whether a single piece or multi-piece including a base, two folding sidewalls and two folding end walls may be comprised of plastic, such as polypropylene, polyethylene, ABS, nylon, carbon fiber, and additionally any product that uses fiberglass and/or carbon fiber, long fiber technology and/or resin such as vinylester, polyester, polyurethane or any other type of resin. The manufacturing methods for manufacturing the container and its components may be injection molding, vacuum forming, thermoforming, Roto molding, compression injection molding, cast molding, or compression molding.

With reference now to the FIGS. 1-3, the container 10 is made up of a base 16, sidewalls 14 and end walls 12. It should be noted that the components named sidewalls 14 and end walls 12 are given these arbitrary names. It is only important that the sidewalls and end walls are opposite walls. They could be referred to in vice versa terminology in the drawings. Still further alternatively, a container may have a square base such that the sidewalls and end walls would be the same size. Corner portions 18 are fixed and extend upwardly form each corner of the base 16. Feet 20 are attached to the bottom of the base 16 and support the entire container on the ground of warehouse/factory floor. The container 10 has a protective polymer coating 30 along the outside surface of the base 16. There is also a protective coating 32 at the outside of the tops of sidewalls 14 and end walls 12. Finally, as seen in FIG. 3, there is a coating 34 on the bottom surface of the base 16.

A container that is intended for very heavy weights and rough use may have more feet than a container that is intended for use to transport lightweight products. The feet such as feet 20 may be integral with the base in that they are all molded as a single part. In use, a container is loaded with product and shipped to its destination. At the destination, the container is collapsed so that it takes up less space where it is then transported for washing and sanitation, if necessary, and then further use. As demonstrated in FIG. 1, the container 10 is shown with all four walls 12 and 14 in the up and latched position. These walls may lay flat, because the hinges 13 and 15 in the end walls 12 and sidewalls 14 respectively allow those walls to rotate and move up and down in the slots 19 and 21 in the corner portions 18. In another feature, not shown, similar containers may be stacked upon each other with the sidewalls and end walls protected by the corner portions that interlock with the respective adjacent containers that are stacked thereon.

These containers and their components may be formed from metal, composite, or polymer materials or combinations thereof. In one example of the present container 10, the container components are formed from a polyurethane/fiber composite that is both solid and strong. Importantly, the urethane material is also relatively lightweight. Also favorably, the polyurethane material is very lightweight and strong.

Still further, all or a part of the components of the container 10, may be over molded or otherwise coated for surface protection. This surface protection provides for UV protection, scratch protection, an antibacterial barrier and extra sealant. The type and amount of over mold or coating is determined based on the use of the container. The protective coating may have a thickness of 0.01 mm to 15 mm, or alternatively about 1 mm to 10 mm, or still further alternatively about 3 mm to 8 mm. In one example where the coating material is a polyurethane, the thickness of the coating on a container is about 5 mm.

As noted, the protective polymer may be a polyurethane material or an elastomer. For use with shipping containers where weight is a substantial commercial issue, a polyurethane polymer is especially favorable for its weight and strength characteristics. These containers are shipped multiple times. The less weight that is shipped, the less cost that is associated with the container. Also, it was found that a relatively thick coating had a problem adhering to itself and was prone to peal off when punctured in testing. A smooth and thin coating was found to adhere better to the container surface.

By insert molding or overmolding the base or sidewalls with the protective coating elastomer, the rigid container material can be protected in specific areas on the container or the whole box sidewalls and/or walls and/or base. After the application of the coating it will become an integral part of the box and protect the rigid structure of the box. The rigid box components can be made from polyurethane, polyethylene, ABS, polyurethane or other polymers, long fiber technology, compression injection molding, compression molding, injection molding, rubber molding, thermoformed molding.

The protective polymer coating has a viscosity as measured in CPS (centipoises) of from about 10 to 10,000 Once applied, it will have a hardness (Shore D scale) of about 10 to 100. SSTM test d 22400. The tensile strength of the polymer is (PS I) from 1000 to 15,000. ASTM test d 412. The polymer may have a tear resistance (pli) Die ASTM D412 of about 100 to 800. The polymer will have an impact resistance (in) of 100 to 400 (ASTM D-256). And the polymer will have an elongation index of elongation (%) from 20 to 600, ASTM test d 412.

In addition, the coating may contain some or all of the following components polyether polyois blend, diethyltoluenediamine, Zeolites, and titanium dioxide. Epichlorhydrin, Bisphebol-A,4-Nonyl Phenol Branched, Benzl Alcohol, Silicon Dioxide, Poly(Terephthaloyl-chloride/p-Penylene-Diamine, 4,4′-Methylenebis 2-methyl-Cyclohexanamine, Tetraecthylene-pentamine, Glycol, Glycerol/EC/PO polymer, Polurea, prepolymer, amine-hydroxyl resin, poloxpylenediamine, diethyltoluenediamine, and poloxpropylenetriamine.

The polymer coating is also preferred to have a smooth surface. A rough coating provides the possibility that dirt and microbes could hide in small unevenness and bumps. The smoothness is measured by a Surface Finish Tester, in one example manufactured by Mitutoyo, Model SV-2100. Surface smoothness is measured on the Ra scale. The smoothness of the polymer coating surface is from about Ra 0.1 to Ra 25, or alternatively about Ra 0.2 to Ra 12.

It is intended that the specification and Figures be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims. 

That which is claimed is:
 1. A reusable container comprising: a base, two folding sidewalls, two folding end walls and latches and hinges; wherein the base comprises a rectangular platform having four corner portions fixed at each of the four corners of the base platform respectively; bottom sides of the end walls and bottom sides of the sidewalls include the hinges and are hingedly connected to the base, wherein the end walls and the sidewalls are mounted on opposite sides of the base respectively; and further wherein each end wall comprises a latch that engages an adjacent sidewall when the sidewall and end wall are rotated in the up position substantially normal to the plane of the bottom of the box; wherein the base comprises a plurality of feet attached thereto on the opposite side of the platform from the corner portions; wherein the base, sidewalls and end walls are at least partially coated with a protective polymer.
 2. A reusable container as described in claim 1, wherein the base, two folding sidewalls and two folding end walls are comprised of plastic.
 3. A reusable container as described in claim 1, wherein the plastic further comprises a polyester resin, vinyl ester resin, polyurethane, fiberglass, carbon fiber, polypropylene, polyethylene, ABS, or nylon or other polymer.
 4. A reusable container as described in claim 1, wherein the feet are substantially monolithic and include essentially no exposed crevices therein.
 5. A reusable container as described in claim 1, wherein the feet are comprised of polyurethane and are mechanically fastened to the base of the box.
 6. A reusable container as described in claim 1, wherein the base is entirely coated with the polymer.
 7. A reusable container as described in claim 1, wherein the protective polymer coating is a urethane product that is applied to the container by overmolding, insert molding, cast molding, compression molding or compression injection molding.
 8. A reusable container as described in claim 1, wherein the protective polymer coating has a thickness of about 0.01 mm to 15 mm.
 9. A reusable container as described in claim 1, wherein the protective coating is comprised of a material selected from the group consisting of polyether polyois blend, diethyltoluenediamine, Zeolites, titanium dioxide, Epichlorhydrin, Bisphebol-A,4-Nonyl Phenol Branched, Benzl Alcohol, Silicon Dioxide, Poly(Terephthaloyl-chloride/p-Penylene-Diamine, 4,4′-Methylenebis 2-methyl-Cyclohexanamine, Tetraecthylene-pentamine, Glycol, Glycerol/EC/PO polymer, Polurea, prepolymer, and amine-hydroxyl resin. 